Tool shank



FIG. 1 is a front perspective view of a tool shank, showing our design;

FIG. 2 is a side view thereof;

FIG. 3 is an end view thereof;

FIG. 4 is an opposite end view thereof; and,

FIG. 5 is a rear perspective view thereof.

The shade lines in the figures show contour and not surface ornamentation. Dashed lines in the drawings depict portions of the tool shank which form no part of the claimed design. 

CLAIM The ornamental design for a tool shank, as shown and described. 